1、Designation: D 7175 05e1Standard Test Method forDetermining the Rheological Properties of Asphalt BinderUsing a Dynamic Shear Rheometer1This standard is issued under the fixed designation D 7175; the number immediately following the designation indicates the year oforiginal adoption or, in the case
2、of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. Asuperscript epsilon (e) indicates an editorial change since the last revision or reapproval.e1NOTEEditorial changes were made to Sections 7 and 8 in October 2005.1. Scope1.1 This test method cover
3、s the determination of the dy-namic shear modulus and phase angle of asphalt binders whentested in dynamic (oscillatory) shear using parallel plategeometry. It is applicable to asphalt binders having dynamicshear modulus values in the range from 100 Pa to 10 MPa. Thisrange in modulus is typically ob
4、tained between 4 and 88C at10 rad/s. This test method is intended for determining the linearviscoelastic properties of asphalt binders as required forspecification testing and is not intended as a comprehensiveprocedure for the full characterization of the viscoelasticproperties of asphalt binders.1
5、.2 This standard is appropriate for unaged materials, ma-terial aged in accordance with Test Method D 2872, materialaged in accordance with Practice D 6521, or material aged inaccordance with both Test Method D 2872 and PracticeD 6521.1.3 This standard may involve hazardous materials, opera-tions, a
6、nd equipment. This standard does not purport toaddress all of the safety concerns, if any, associated with itsuse. It is the responsibility of the user of this standard toestablish appropriate safety and health practices and deter-mine the applicability of regulatory limitations prior to use.2. Refe
7、renced Documents2.1 ASTM Standards:2C 670 Practice for Preparing Precision and Bias Statementsfor Test Methods for Construction MaterialsD 140 Practice for Sampling Bituminous MaterialsD 2170 Test Method for Kinematic Viscosity of Asphalts(Bitumens)D 2171 Test Method for Viscosity of Asphalts by Vac
8、uumCapillary ViscometerD 2872 Test Method for Effect of Heat and Air on RollingFilm of Asphalt (Rolling Thin Film Oven Test)D 6373 Specification for Performance-Graded AsphaltBinderD 6521 Practice for Accelerated Aging of Asphalt BinderUsing a Pressurized Aging Vessel (PAV)E77 Test Method for Inspec
9、tion and Verification of Ther-mometersE 563 Practice for Preparation and Use of an Ice-Point Bathas a Reference TemperatureE 644 Test Methods for Testing Industrial Resistance Ther-mometersE 882 Guide for Accountability and Quality Control in theChemical Analysis Laboratory2.2 AASHTO Standards:R29 P
10、ractice for Grading or Verifying the PerformanceGrade of an Asphalt Binder3T315 Standard Test Method for Determining the Rheologi-cal Properties of Asphalt Binder Using a Dynamic ShearRheometer32.3 Deutsche Industrie Norm (DIN) Standard:43760 Standard for Calibration of Thermocouples43. Terminology3
11、.1 Definitions of Terms Specific to This Standard:3.1.1 annealing, nthe process of removing the effects ofsteric hardening by heating the binder until it is sufficientlyfluid so that it can be easily poured.3.1.2 asphalt binder, nan asphalt-based cement that isproduced from petroleum residue either
12、with or without theaddition of non-particulate modifiers.3.1.3 calibration, nprocess whereby the accuracy andprecision of a device are checked against NIST-traceablestandards and where necessary adjustments are made to thedevice to correct its operation or precision and accuracy.3.1.3.1 DiscussionCa
13、libration is typically performed bythe manufacturer or an external commercial calibration service.1This test method is under the jurisdiction of ASTM Committee D04 on Roadand Paving Materials and is the direct responsibility of Subcommittee D04.44 onRheological Tests.Current edition approved Sept. 1
14、5, 2005. Published October 2005.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. For Annual Book of ASTMStandards volume information, refer to the standards Document Summary page onthe ASTM website.3Available from American Asso
15、ciation of State Highway and TransportationOfficials (AASHTO), 444 N. Capitol St., NW, Suite 249, Washington, DC 20001.4Available from Beuth Verlag GmbH (DIN- DIN Deutsches Institut furNormung e.V.), Burggrafenstrasse 6, 10787, Berlin, Germany.1Copyright ASTM International, 100 Barr Harbor Drive, PO
16、 Box C700, West Conshohocken, PA 19428-2959, United States.3.1.4 complex shear modulus (G*), nratio calculated bydividing the absolute value of the peak-to-peak shear stress, t,by the absolute value of the peak-to-peak shear strain, g.3.1.5 dummy test specimen, na specimen formed betweenthe DSR test
17、 plates from asphalt binder or other polymer forthe purpose of determining the temperature in the asphaltbinder between the plates.3.1.5.1 DiscussionThe dummy test specimen is not usedto measure the rheological properties of asphalt binder but isused solely to determine temperature corrections.3.1.6
18、 linear viscoelastic, adjwithin context of this testmethod, refers to a region of behavior in which the dynamicshear modulus is independent of shear stress or strain.3.1.7 loading cycle, nrefers to the application of sinusoi-dal stress or strain loading for a specified duration of time.3.1.8 molecul
19、ar association, nrefers to time-dependentassociations that occur between asphalt binder moleculesduring storage at ambient temperature.3.1.8.1 DiscussionOften referred to as steric hardening inthe asphalt literature, molecular associations can significantlyincrease the dynamic shear modulus of aspha
20、lt binders.3.1.8.2 DiscussionThe effect of molecular association orsteric hardening on the dynamic shear modulus is asphaltspecific and may be apparent even after a few hours of storage.3.1.9 oscillatory shear, nrefers to a type of loading inwhich a shear stress or shear strain is applied to a test
21、samplein an oscillatory manner such that the shear stress or strainvaries in amplitude about zero in a sinusoidal manner.3.1.10 parallel plate geometry, nrefers to a testing geom-etry in which the test specimen is sandwiched between tworigid parallel plates and subjected to shear.3.1.11 phase angle
22、(d), nthe angle in degrees between asinusoidally applied strain and the resultant sinusoidal stress ina controlled-strain testing mode, or between the applied stressand the resultant strain in a controlled-stress testing mode.3.1.12 steric hardening, nsee molecular association.3.1.13 portable thermo
23、meter, nrefers to an electronicdevice that is separate from the dynamic shear rheometer andthat consists of a detector (probe containing a thermocouple orresistive element), associated electronic circuitry, and readoutsystem.3.1.14 reference thermometer, nrefers to a NIST-traceableliquid-in-glass or
24、 electronic thermometer that is used as alaboratory standard.3.1.15 temperature correction, ndifference in temperaturebetween the temperature indicated by the DSR and the testspecimen as measured by the portable thermometer insertedbetween the test plates.3.1.16 thermal equilibrium, ncondition where
25、 the tem-perature of the test specimen mounted between the test platesis constant with time.3.1.17 verification, nprocess of checking the accuracy ofa device or its components against an internal laboratorystandard. Usually performed internally within the operatinglaboratory.4. Summary of Test Metho
26、d4.1 This standard contains the procedure used to measurethe complex shear modulus (G*) and phase angle (d) of asphaltbinders using dynamic shear rheometer and parallel plategeometry.4.2 The standard is suitable for use when the dynamic shearmodulus varies between 100 Pa and 10 MPa. This range inmod
27、ulus is typically obtained between 4 and 88C, dependingupon the grade, test temperature, and conditioning (aging) ofthe asphalt binder.4.3 Test specimens, nominally 25 mm in diameter by 1 mmthick or 8 mm in diameter by 2 mm thick, are formed betweenparallel metal plates.4.4 During testing, one of th
28、e parallel plates is oscillatedwith respect to the other at pre-selected frequencies andangular deflection (or torque) amplitudes. The required ampli-tude depends upon the value of the complex shear modulus ofthe asphalt binder being tested. The required amplitudes havebeen selected so that, for mos
29、t asphalt binders, the testingspecified in this standard is within the region of linear behavior.4.5 The test specimen is maintained at the test temperature6 0.1C by enclosing the upper and lower plates in a thermallycontrolled environment or test chamber.4.6 Oscillatory loading frequencies using th
30、is standard canrange from 1 to 160 rad/s. Specification testing is performed ata test frequency of 10 rad/s. The complex modulus (G*) andphase angle (d) are calculated automatically as part of theoperation of the rheometer using proprietary computer soft-ware supplied by the instrument manufacturer.
31、5. Significance and Use5.1 The test temperature for this test is related to thetemperature experienced by the pavement in the geographicalarea for which the asphalt binder is intended to be used.5.2 The complex shear modulus is an indicator of thestiffness or resistance of asphalt binder to deformat
32、ion underload. The complex shear modulus and the phase angle definethe resistance to shear deformation of the asphalt binder in thelinear viscoelastic region. The complex modulus and the phaseangle are used to calculate performance-related criteria inaccordance with Specification D 6373.6. Interfere
33、nces6.1 Particulate material in the asphalt binder is limited toparticles with longest dimensions less than 250 m. Particleswith dimensions greater than 250 m approach the dimensionsof the gap (1000 m). In order to accurately characterize atwo-phase material containing particulate material it is wel
34、laccepted that the thickness of the test specimen must be at leastfour times the maximum particle size.6.1.1 The calculation of the complex modulus from the dataobtained from the DSR is highly dependent upon an accuratemeasurement of the diameter of the test specimen. In theprocedure, the diameter o
35、f the test specimen is assumed equalto the diameter of the test plates. This assumption is valid onlyif the test sample is properly trimmed.6.1.2 The physical properties of asphalt binders are verysensitive to test temperature and thermal history. ThermalD717505e12history is the number of times asph
36、alt binder sample has beenheated prior to testing. Controlling the test temperature to6 0.1C and limiting the number of times the asphalt sample isheated prior to testing (only one heating is recommended) isessential in order to obtain repeatable test results within alaboratory as well as to reprodu
37、ce results between laboratories.7. Apparatus7.1 Dynamic Shear Rheometer (DSR) Test SystemA dy-namic shear rheometer test system consisting of parallel metalplates, a means for controlling the temperature of the testspecimen, a loading device, and a control and data acquisitionsystem.7.1.1 Test Plate
38、sMetal plates cylindrical in shape, formedfrom steel or aluminum, with smooth ground surfaces. Twoplates 8.00 6 0.1 mm in diameter and two plates 25.00 6 0.5mm in diameter as described in Fig. 1 are required. The testplates shall have a minimum thickness or raised portion of 1.5mm to allow sufficien
39、t clearance for trimming the specimen.The plates shall be formed as an integral part of the test fixturesthat are used to mount the plates in the DSR.NOTE 1The upper and lower plates should be concentric with eachother.At the present there is no suitable procedure for the user to check theconcentric
40、ity except to visually observe whether or not the upper andlower plates are centered with respect to each other. The moveable plateshould rotate without any observable horizontal or vertical wobble. Thismay be checked visually or with a dial gage held in contact with the edgeof the moveable plate wh
41、ile it is being rotated.7.1.2 Environmental ChamberA chamber for controllingthe temperature of the test specimen. The medium for heatingand cooling the specimen in the environmental chamber shallnot affect asphalt binder properties. The temperature in thechamber may be controlled by the circulation
42、of fluidconditioned gas, nitrogen or water is acceptableor by asuitable arrangement of actively temperature controlled heatingelements (for example, solid state Peltier elements) surround-ing the sample. When laboratory air is used in a forced airoven, a suitable dryer must be included to prevent co
43、ndensa-tion of moisture on the test plates. The environmental chamberand the temperature controller shall control the temperature ofthe test specimen mounted between the test plates, includingany thermal gradients within the test specimen, at the testtemperature 6 0.1C. The chamber or the water in t
44、he chambershall completely enclose the top and the bottom plates tominimize thermal gradients within the fixtures and test speci-men.NOTE 2Acirculating bath unit, separate from the DSR that pumps thewater through the test chamber may be required if a fluid medium is used.7.1.2.1 Temperature Controll
45、erA temperature controllercapable of maintaining the temperature of the test specimen atthe test temperature 6 0.1C for test temperatures rangingfrom 4 to 88C.7.1.3 Internal DSR ThermometerA platinum resistancethermometer (PRT) mounted within the environmental cham-ber as an integral part of the DSR
46、 and in close proximity to thefixed plate, with a range of 4 to 88C, and with a resolution of0.1C. This thermometer shall be used to control the tempera-ture of the test specimen between the plates and shall providea continuous readout of temperature during the mounting,conditioning, and testing of
47、the specimen.NOTE 3Platinum resistance thermometers (PRTs) meeting DIN Stan-dard 43760 (ClassA) or equal are recommended for this purpose. The PRTis to be calibrated as an integral unit with its respective meter or electroniccircuitry.7.1.4 Loading DeviceThe loading device shall be capableof applyin
48、g a sinusoidal oscillatory load to the specimen at afrequency of 10.0 6 0.1 rad/s. If frequencies other than 10rad/s are used, the frequency shall be accurate to 1 percent. Theloading device shall be capable of providing either a stresscontrolled or strain controlled load within a range of stress or
49、strain necessary to make the measurements described in thisstandard. The manufacturer of the device shall provide acertificate certifying that the frequency, stress, and strain arecontrolled and measured with accuracy of 1 % or less in therange of this measurement.7.1.5 Data Acquisition SystemThe data acquisition sys-tem shall provide a record of temperature, frequency, deflectionangle, and torque. The manufacturer of the rheometer shallprovide a certificate certifying that the frequency, deflectionangle, and torque are reported with an acc
